Terrified, yet cooler than the average man would have been, he caught up a shoe that his bare foot had brushed. Running to the window, he pressed it hard on the ledge, scraping off a blob of mud that adhered to it. Then he threw the curtain far to one side. Tossing the shoe back under the bed, he bolted for his own room.

On the way he stopped long enough to take the key from the lock, insert it on the outer side, lock the door, pocket the key and glide back to his adjoining room, just as Macduff’s wild wolf-howl awakened the house.

There, shivering and cursing his own stupidity, he crouched for a minute before venturing out into the hall to join the aroused guests.

He had made it seem the murderer had entered and gone out through the window. He felt safe enough, but sick with chagrin.

During that eternal minute of waiting he, perforce, changed his whole line of action. He had failed to rid himself of his foe. The only move left to him was to strive to fix the murder on Vail. And this, both as Clive and as Osmun, he proceeded with all his might to do.

In telling this to Clive when they met next day at Rackrent Farm he declared passionately that he would have succeeded in sending Thaxton to prison and perhaps to execution but for Miss Gregg’s inspired lie—which he accepted as truth—and for the item of the shoeprint on the window-sill.

Checkmated at every turn and dreading to see any one until he could rearrange his shattered line of action, he went secretly to Rackrent Farm. He calculated that his fabrication about a gas-explosion in the laboratory, there, would prevent acquaintances from seeking him at the farmhouse.

In endorsement of the gas story he already had given his two negro house-servants a week’s holiday and had had them taken by taxi to Pittsfield. So the coast would be clear.

Arrived at the farm, he strayed into the laboratory. Chemistry and chemical experiments had ever been the chief amusement of the twins. Their laboratory was as finely equipped as that in many a college. They had spent money and time and brains on it for years.

When the laboratory had been moved to Rackrent Farm from Canobie it had been set up in a large rear room. Here in leisure hours Osmun still pottered with his loved chemicals.